It seems that '-sel' is no longer supported. The profile should only select eng audio or audio with no language. However in my case English and German audio tracks are selected (the only two trakcs on that BD).

Any modified XML profiles should be stored in your MakeMKV data directory. And the selection rules in a profile are used unless you override them in the Advanced tab. In a profile, there SHOULD be quotes around the string, but not in the advanced tab.

You can start by copying a "stock" profile, which, in recent versions, are stored in appdata.tar in your MakeMKV program directory. Since you're on Linux, opening a TAR file is simple; you can extract everything into a directory, or just the xml files, if you want.

MakeMKV ships with four profiles:

aac-st.mmcp.xml
default.mmcp.xml
flac.mmcp.xml
wdtv.mmcp.xml

Comments within the files explain much of what is being done. Here is the current "default.mmcp.xml" file contents: